40 lines
1.0 KiB
Go
40 lines
1.0 KiB
Go
// Copyright (c) HashiCorp, Inc.
|
|
// SPDX-License-Identifier: MPL-2.0
|
|
|
|
/*
|
|
Package mutex implements the sync.Locker interface using x/sync/semaphore. It
|
|
may be used as a replacement for sync.Mutex when one or more goroutines need to
|
|
allow their calls to Lock to be cancelled by context cancellation.
|
|
*/
|
|
package mutex
|
|
|
|
import (
|
|
"context"
|
|
|
|
"golang.org/x/sync/semaphore"
|
|
)
|
|
|
|
type Mutex semaphore.Weighted
|
|
|
|
// New returns a Mutex that is ready for use.
|
|
func New() *Mutex {
|
|
return (*Mutex)(semaphore.NewWeighted(1))
|
|
}
|
|
|
|
func (m *Mutex) Lock() {
|
|
_ = (*semaphore.Weighted)(m).Acquire(context.Background(), 1)
|
|
}
|
|
|
|
func (m *Mutex) Unlock() {
|
|
(*semaphore.Weighted)(m).Release(1)
|
|
}
|
|
|
|
// TryLock acquires the mutex, blocking until resources are available or ctx is
|
|
// done. On success, returns nil. On failure, returns ctx.Err() and leaves the
|
|
// semaphore unchanged.
|
|
//
|
|
// If ctx is already done, Acquire may still succeed without blocking.
|
|
func (m *Mutex) TryLock(ctx context.Context) error {
|
|
return (*semaphore.Weighted)(m).Acquire(ctx, 1)
|
|
}
|